Half to daniel p



2 Sheets-Sheet 1. 0. ROBERTS, STEAM ENGINE.

(NQMOdGL) No. 364,374. PatentefiJune 7, 1887.

IN VEN TQR WITNESSES: i

ATTORNEYS (No Model.) 2 Sheets-Sheet 2.

F. 0'. ROBERTS.

STEAM ENGINE.

No. 364,874. Patented June 7, 1887.

WITNESS u. PETERS. Phmumo m Wnhington. u. c.

UNITED STATES PATENT OFFICE.

FREDERICK O. ROBERTS, OF MOHAXVK, NEYV YORK, ASSIGNOR OF ONE- HALF TO DANIEL P. VAN COURT, OF SAME PLACE.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 364,374, dated June 7, 1887.

Application filed January 17, 1887.

.To all whom it may concern.-

Be it known that I, FREDERICK G. RoBERTs, of Mohawk, in the county of Herkimer, in the State of New York, have invented new and useful Improvements in Steam-Engines, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention consists in a novel construction of a steam-engine in which the friction of the piston is reduced to a minimum and the steam-pressure is applied to the piston in the most advantageous manner, all as hereinafter more fully described, and specifically set forth in the claims.

.The invention is fully illustrated in the annexed drawings, wherein Figure 1 is a side elevation of a steam-engine embodying my invention. Fig. 2 is an enlarged face view of the side of the cylinderto which the steamchest is attached, the cover of the latter being removed to showthe in tcrior of the steam chest; and Fig. 3 is a transverse section of thesteamcylinderwith thesteam-ehestsattachedthereto.

Similar letters of reference indicate corresponding parts.

A represents the stcamcyli nder, which I divide into longitudinal compartments A A, of equal dimensions, by hollow longitudinal partitions P P, of sectoral form, in erosssection.

G O are oscillatory pistons, preferably formed in one piece, to insure their operation in unison, and also to reduce the cost of manufacture. These pistons consist of plates extending the length and width of the compart ments A A, and fitted with their edgcsste'alntight to said compartments. They are pivoted in the axis of the cylinder A, and are formed with a cylindrical enlargement, a, along their axial portion. In order to fit the said pistons steam-tight to the partitions PP, I provide the latter with longitudinal grooves 1), adjacent to the axial enlargement a of the pistons, and in said grooves I place adj ustabl y the anti-friction metal packing strips or gibs c, which I bring to bear on the portion a of the joined pistons by means of setscrews d (I, introduced into the hollow partition, and inserted in screw-threaded holes extending from the cavities of the partitions to the grooves b,

merely is that of an ordinary slide-valve.

Serial No.22l,579. '(Nomodch) v as shown in Fig. 3 of the drawings. The edges of the pistons I provide with longitudinal grooves, in which I secure antifriction metal packing strips or facings e, by which the pistons are fitted steam-tightto the compartments A A.

f f denote steam-ports extending through the sides of the cylinder at opposite sides of the respective partitions P P, and h h denote exhaust-portsin the outer portions of the aforesaid partitions, between the steam-ports. The exterior of the cylinder A is formed with valveseats e e, at the sides through which the aforesaid ports are extended, and upon said valve-seats are placed the valves D D, inclosed in the steam-chests F F. Said valves may be of any suitable and wellknown form. The form here illustrated for GXGDIPllfiCZLlCJDlOII he two valves D D are reciprocated alternately in opposite directions from each other, and as one valve admits live steam to one compartment A, at one side, the other valve allows the steam to exhaust from said compartment, at the opposite side, and thus the intervening piston G is forced from one side of the compartment to the opposite side thereof; and inasmuch as the ingress and egress of steam-of the two compartments is reverse and the two pistons are united, they are compelled to operate in unison and with double force.

The described duplex piston is provided at opposite ends with trunnions, one or both of which project through stuffing-boxes a on the exterior of the cylinder, and to the protruding ends of said trunnion is attached a crank, L, from which motion is transmitted to the main driving-shaft 0 bya shorter crank, it, attached to said shaft, and connected with the crank L by the connecting-rod N, as represented in Fig. 1 of the drawings. To the driving-shaft is also attached the eccentric a, from which to transmit motion to the valves D D. The means for transmitting this motion maybe varied,.

and can be devised by any engineer of ordinary skill.

For exemplilication, I have shown a bellcrank, one arm of which is connected with the eccentric-rod r, and the other arm is connected by a rod, 8, with a Walking-beam, H, the two ends of which are connected, respectively,with the rods or stems of the valves D D by intermediate links,z' 11. Z Z represent the steampipes,which conduct the steam from the boiler to the-steam-chests, and t t denote the exhaustpipes.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, 18-

1. A steam-engine comprising a stea1n-cylinder having at dianietrically-opposite sides sectoral longitudinal partitions, steam-ports through the side of the cylinder at opposite sides of each of said partitions, exhaust-ports in the partitions,steam-chests and valves on the exterior of the cylinder and respectively over the aforesaid ports, oscillatory pistons formed in one piece, with 'a cylindrical enlargement along the axial portion pivoted in the axis of the cylinder and extending the length and width of the compartments of the cylinder, and adjustable bearings between the axial portion of thepiston and the adjacent portion of the partitions, as set forth and shown.

2. The combination of the steam-eylinder divided into compartments by hollow longitudinal partitions, oscillatory pistons formed in one piece with a cylindrical enlargement along the axial portion and pivoted in the axis of the cylinder, gibs adj ustably connected to the partitions adjacent to-the axial portions of the pistons, set-screws extending from the cavities of the hollow partitions to the gibs for adj usting the same, and anti-friction facingssecured to the pistons along the edges thereof, substantially as described and shown.

Intestimony whereof I have hereunto signed my name and affixed my seal, in the presence of two attesting witnesses, at Mohawk, in the county of Herkimer, in the State of New York, this 23d day of December, 1886.

FREDERICK o. ROBERTS. 1. SI]

Witnesses:

J OHN MoOHEsNEY, E. L. PRINCE. 

